Rebekah -- to answer your question, my soil here in western Kentucky is very acidic.
And a word of warning -- composting is a good thing -- but it is easy to over-do. Irises will tolerate almost anything except poor drainage. So a little bit of compost in your clay soil will benefit them -- but composting to the point of the soil being slow to dry can cause rot.
Also -- any Irises that you buy at the big box stores cannot be deemed to be correctly identified. Packaged Irises are notorious for being completely mis-identified. The only way to be sure that you have purchased the Iris that you want, is to buy it directly from an Iris vendor. And sometimes even THEY make a mistake.
